Soles equipping sports shoes of this type are subjected to relatively intensive use and abrasion because of the nature and the variety of golf courses, more commonly called "greens," and by the great distances covered. Users remark particularly on the rapid wearing, and indeed even of the breakage, of the stud heads, as well as on the accumulation of dirt and grass which stick to the bases of the studs, thereby reducing their functional life. Furthermore, because the number of studs under the walking sole is limited, the supporting surface provided by this sole becomes greatly reduced, especially on hard courses where gripping is exerted only by the heads of the studs. As a result, the pressures channelled to the studs often cause deformations of the sole, which produce painful sensations on the golfer's soles.
A large number of studded soles intended in particular for golfing have been designed so as to ensure conditions which facilitate the gripping of the ground. In addition, some soles are equipped with studs whose heads are made of a relatively hard material to reduce wear and tear.
The Japanese Patent No. 59.28902 may be cited as an example. This patent describes both studs whose structure may comprise heads of a hard material and methods for fastening such studs within the thickness of the shoe sole. As the drawings show, the hard head of the stud is not anchored in the body of the stud, whose point of attachment, in a first illustrated case, is greatly recessed from the tip and from the walking surface, or, in a second illustrated case, is almost flush with said walking surface and exerts a renewed gripping action on the walking surface by means of a raised flange. A structure and an fastening system of this kind do not protect against the possible loss of the hard tip, given the absence of anchoring, and they do not prevent the accumulation of dirt and/or grass, since the connection of said tip in relation to the walking surface forms a sharp angle, i.e., a raised edge.
Other studded soles, of the type described in the German Patent Application No. Dgm 75 01 105, comprise studs whose attachment within the sole is composed of a dovetail slide-track, and whose heads, substantially in the shape of a conical frustum, are attached at a sharp angle to said studs. A stud design of this type, according to which the base is flush with the walking surface of the sole, does not lessen the risks of accumulating dirt, and proves to be relatively complicated and troublesome because of the means of attachment.